| 题名 | CE-ICP-MS联用技术在形态分析及纳米颗粒表征中的应用 |
| 作者 | 刘丽红 |
| 学位类别 | 博士 |
| 答辩日期 | 2015-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 江桂斌 ; 何滨 |
| 关键词 | CE-ICP-MS 联用技术 砷 硒 纳米颗粒, CE-ICP-MS, hyphenated techniques, arsenic, selenium, nanoparticles |
| 其他题名 | Application of CE-ICP-MS in speciation analysis and nanoparticle characterization |
| 学位专业 | 环境科学 |
| 中文摘要 | 环境中广泛存在的砷、硒化合物对人类健康具有重大的影响。砷是一种剧毒致癌物质，硒是对人体和生物体健康具有重要作用的微量元素，但高剂量的硒对生物体也 具有毒性效应。纳米材料由于特殊的性能近年来得到了突飞猛进的发展，其在生产、生活中的应用越来越广泛，同时也对生态环境和人体健康带来了潜在的危害。 砷、硒化合物以及纳米颗粒在环境中不断迁移转化，可以通过直接摄入或者食物链传递的方式进入人体，对人体健康造成影响。砷、硒化合物化学形态的不同，以及 纳米颗粒组成、粒径和表面电荷等物理形态的不同，它们在环境和生物体内的迁移转化规律、生物活性或毒性效应以及产生的危害也各不相同，直接影响了它们的环 境行为和生态毒性。因此，要研究环境中元素化学形态及纳米颗粒的环境行为和毒理效应，发展环境中砷、硒和纳米颗粒等的化学或物理形态的分析方法具有非常重 要的意义，尤其是纳米颗粒的分析表征方法遇到了新的挑战。另一方面，毛细管电泳与电感耦合等离子体质谱（CE-ICP-MS）联用技术是一种强大的分析检 测工具，已被广泛应用于不同元素的形态分析中。但是CE-ICP-MS联用技术的关键部分，即接口设计，仍然是影响该技术分离效率和检测灵敏度的重要因 素。本论文工作主要是建立在CE-ICP-MS联用技术的基础上，设计新型、简单、高效的接口，为复杂环境和生物样品中砷、硒化合物的形态分析以及纳米颗 粒的表征提供灵敏可靠的方法。 实验中首次将CE-ESI-MS喷雾针改装后作为连接CE与ICP-MS的接口，建立了一种CE-ICP-MS在线联用技术分离检测10种砷化合物的方 法。与传统接口相比，该接口消除了毛细管与雾化器之间的死体积，很大程度上提高了样品的雾化效率，具有分离效率高、稳定性好和重现性好等优势。经过对分离 条件和检测条件的优化，10种砷化合物在30min内达到完全的基线分离，标准曲线线性良好，各种砷化合物的迁移时间、峰高和峰面积之间的相对标准偏差 RSD（n=5）分别小于1.5%、5.7%和4.8%，检出限在0.9至3.0 μg L -1之间。该方法成功应用于地下水、中草药、鸡肉样品及标准参考物质DORM-3和TORT-2中不同砷形态化合物的分离检测，回收率为 94%~110%，可应用于不同环境样品中砷的形态分析。 在前期接口设计的基础上，针对ICP-MS标准雾室死体积大的问题，设计了一个直接进样的全耗型雾室，并与喷雾针联用作为CE-ICP-MS联用系统的接 口，建立了同时进行多种砷、硒化合物形态分析的方法。该接口最大程度地消除了系统的死体积，极大地提高了样品的传输效率，同时具有鞘流液低速稳定、雾化效 率高、稳定性好等优势。通过使用该接口，建立了分离6种砷化合物和5种硒化合物的形态分析方法，不同砷、硒化合物在9分钟内达到完全的基线分离。该方法 中，砷化合物的检出限为0.11 – 0.37 μg L-1，硒化合物的检出限为1.33 – 2.31 μg L-1。该方法6次进样的迁移时间和峰面积的相对标准偏差均小于2.68%（砷化合物）和3.28%（硒化合物）。该方法成功应用于标准参考物质 DORM-3、水样、尿液样品和鱼样等样品中砷和硒化合物的分析检测。 首次利用电泳分离和ICP-MS检测的联用技术建立了一种鉴定和精确表征复杂基质中纳米材料的新方法。不同粒径的纳米颗粒和相应的离子根据电泳淌度的不同 通过CE实现分离，并通过ICP-MS对纳米材料进行组成成分的定性分析和浓度的定量分析，再利用高斯拟合得到纳米颗粒的平均粒径分布。该方法可以通过一 次测量得到纳米材料的多维信息，包括纳米材料的组成成分、平均粒径和粒径分布、离子态及浓度信息等。实验中以纳米银和纳米金为例，实现了不同粒径纳米银、 银离子以及不同粒径纳米金、金离子的同时分离、表征和定量，并可以应用于实际纳米产品中纳米银的快速筛查与检测。与常规的表征方法相比，该方法对纳米材料 的表征结果更准确，为复杂基质中多分散纳米体系中纳米材料的表征提供了强大的工具。 |
| 英文摘要 | Arsenic and selenium in environment have significant influence to human health. Arsenic is concerned as a poison and carcinogen. Selenium is recognized as an essential trace element for human and biological systems. However, selenium is also a potential toxicant at high doses. Moreover, with the rapidly development of nanotechnologies and extensive application of nanomaterials in recent decades, new concerns for the potential adverse effects of nanoparticles on human health and ecosystem have been raised. Both arsenic and selenium, as well as nanoparticles can migrate and transform in the environment and human body directly or through the food chain to cause toxic effect. Their behavior and fate in environment, biological/toxic activity and relative damage to human are highly dependent not only on the concentration, but also on the chemical form and physical species, such as size, shape and surface charge. Therefore, to better understand the behavior and toxicology of element species and nanoparticles in the environment, it is of great importance to develop robust and sensitive analytical method for speciation of arsenic, selenium and nanoparticles. Particularly, the method for nanoparticle characterization and analysis has faced new challenges. Capillary electrophoresis coupled with inductively coupled plasma mass spectrometry (CE-ICP-MS) is a powerful tool for speciation analysis and has been applied for speciation of various elements. The key factor of this hyphenated technique is the interface design, which has significant effects on the separation resolution and detection sensitivity. Up to now, there is still an urgent need for more efficient interfaces coupling CE with ICP-MS. The aim of this work is (1) to design new, simple and efficient interface of CE-ICP-MS, (2) to develop rapid, sensitive and robust method for speciation of arsenic and selenium, and (3) to establish novel method for characterization and analysis of nanoparticles in the environmental samples. For designing a new connection box, a CE-ESI-MS sprayer kit was firstly fabricated as the interface for coupling CE with ICP-MS and a method for speciation of ten arsenic compounds was developed based on this novel interface. The interface eliminated the dead volume between the outlet of the capillary and the interface, greatly improved the sample nebulization efficiency and maintained several advantages, such as high resolution, good stability and great reproducibility. After optimization of the separation and analytical conditions, baseline separation of the ten arsenic species was achieved within 30 mins by using an electrophoretic buffer consisting of 12 mM NaH2PO4 and 8 mM HBO3 at pH 9.20 with an applied voltage of +30 kV. The detection limits of the ten arsenic compounds ranged from 0.9 to 3.0 ng As g-1, and the relative standard deviations (RSD, n = 5) were below 1.5%, 5.7% and 4.8% for migration time, peak height and peak area, respectively. This method was successfully applied for the determination of various arsenicals in two certified reference materials (TORT-2 and DORM-3) and some environmental samples such as ground water samples, herbal plants and chicken meat. A novel direct injection high efficiency nebulizer (DIHEN) chamber was designed to replace the standard Scott nebulizer chamber of ICP-MS in order to reduce the large dead volume of the system. The CE-ESI-MS sprayer was fitted on this home-made chamber and used as the interface of CE-ICP-MS system. Minimum dead volume, low and steady sheath flow liquid, high nebulization efficiency and high sample transport efficiency were obtained by using this interface. A simple and highly efficient on-line CE-ICP-MS method for simultaneous separation and determination of arsenic and selenium compounds was then developed. Six arsenic species and five selenium species were baseline separated and determined in a single run within 9 min under the optimized conditions. Detection limits were in the range of 0.11 – 0.37 μg L-1 for arsenic compounds and 1.33 – 2.31 μg L-1 for selenium species. Repeatability expressed as the relative standard deviations (RSD, n = 6) of both migration time and peak area were better than 2.68% for arsenic and 3.28% for selenium, respectively. The proposed method had been successfully applied for the determination of arsenic and selenium species in the certified reference materials DORM-3, water, urine and fish samples. It remains extremely difficult to identify and characterize nanoparticles (NPs) in complex media. Here, we established a new method for identifying and accurately characterizing the size of NPs in complex media based on capillary electrokinetic separation coupled to inductively coupled plasma mass spectrometry (ICP-MS) for the first time. Different sized nanoparticles and their relative element ions were separated based on their different electrophoretic mobility and then transported to ICP-MS for qualitative and quantitative analysis. Through mass scanning and Gaussian fitting of electropherogram peaks, we could obtain multi-dimensional information on chemical compositions, size distributions, and ionic species of multiple NPs in a single run. Taking silver and gold nanoparticles as an example, the different sized silver nanoparticle, gold nanoparticle, silver ions and gold ions were simultaneously separated, characterized and quantified within a single run. The results are more accurate than those obtained with conventional methods. This method provides a powerful tool for investigating polydisperse NP systems and rapid screening of NP-containing products. |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/34503]  |
| 专题 | 生态环境研究中心_环境化学与生态毒理学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 刘丽红. CE-ICP-MS联用技术在形态分析及纳米颗粒表征中的应用[D]. 北京. 中国科学院研究生院. 2015. |
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